Albert w



(No Model.)

A. W. SMITH.

ELECTRIC ARC LAMP.

No. 541,460. Patenked June 25, 1895. 7

UNITED STATES PATENT OFFICE.

ALBERT \V. SMITH, OF \VASHINGTON, DISTRICT OF COLUMBIA.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 541,460, dated June 25, 1895.

Application filed April 2 5, 189 5.

To o/ZZ whom it may concern:

Be itknown that I, ALBERT W. SMITH, a citizen of the United States, residing at Washington, in the District of Columbia, have invented an Improvement in Are Lamps, of which the following is a specification.

The object of this invention is to provide a cheap, simple, and reliable arc lamp.

To-this end the invention consists of a coiled or bent tube or other tortuous passage secured to the movable carbon support, and a flexible metallic ribbon passing through said tube or passage, one end of said ribbon being connected to the lamp mechanism and receiving motion therefrom, while its other end is weighted to cause the ribbon to bind in said tube or passage.

In the drawings herewith, Figure l is a side view. Fig. 2 is a section on line 00, Fig. 1.

a a are side rods and b b are tie pieces forming the lamp frame.

0 is the movable carbon support sliding on rods a a.

(Z is a solenoid secured on upper tie piece Z).

i is a bent tube brazed to support 'i'.

g is the movable carbon holder having screw 9 screwing into support 6, thus securing both holder g and tube 6 to the movable carbon support 0.

h is the fixed carbon holder.

75 is the movable carbon, and z" is the fixed carbon.

is a solenoid core having screwed into it the stemj, on which is the eollarj adapted to retain core j against the action of gravity.

It is a flexible metallic ribbon passing through tube 6. The upper end of ribbon 7c is secured to the insulating nipple Zr, which is secured to core j. To the lower end of ribbon 7.; is secured the tension weight Z, guided on adjustable pin Z. The rubber nipple Z insulates weight Z from ribbon 7a.

m is an insulating bushing through which the ribbon 7c passes freely, and serves to insulate it from movable support 0.

The circuit through the lamp is as follows: Beginning at positive terminal 01 it passes through solenoid (I, then by way of flexible connection 1) to ribbon 75, to tube 6, to upper carbon holder g, through carbons i and Z, and out at negative terminal or.

Serial No. 547,073- (No model.)

The operation of the lamp is as follows: When the lamp is out of action the corej drops down until retained by collarf. The weight Z comes to rest on the top end of pin Z, thus removing all tension from ribbon it, when carbon 2' and its attachments descend under the action of gravity until carbon 1' comes into contact with and rests on carbon i. If now the lamp is switched into circuit, the core j is drawn up and with it ribbon 7t, until the tension weight Z is lifted from pin Z, when by reason of the friction caused between ribbon 7c and tube 8 by the weight Z, the entire movable support 0 and its attachments are lifted until carbons Z and c" are sufficiently separated to form the arc. As the carbons are consumed and the arc lengthens, more current flows through shunt circuit 1) p, weakening solenoid cZ, when corej gradually descends until weightZ comes partly or wholly to rest on top of pin Z, thus partly or wholly removing the tension on ribbon Z13 and consequently the friction between ribbon 7t and tube 6, and thus permitting the movable carbon and its attachments to descend by grav ity the necessary amount, and thus maintain a constant arc length.

In Fig. 2 is shown a section of tube e on line 0;, Fig. 1, showing the form of cross section of tube 6.

In addition to causing the feed of the carbons, ribbon 7; also performs the function of conveying the current to movable carbon 1', thus avoiding the use of a flexible conducting cord, or other devices for this purpose.

With many lamps now in use there is considerable delay in the feeding of the carbons. This is due to the fact that at the moment of feeding a considerable portion of the mechanism comes to rest against a stop or other device, thus causing what is termed holding up, and eventually overfeeding of the carbons. In my lamp the small weight Z is the only thing that comes to rest in the feeding position, and as it is very small it causes no holding up, by reason of its weight being removed from the lamp mechanism.

Another defect common to most lamps now in use is uneven and jerky feeding, causing unsteadiness of light, and great variation of circuit resistance. In my lamp the feed is very gradual and practicallycontinuous, there being a gradual release of the support 0. As weight Z touches pin Z, jerky motion or overfeeding is entirely prevented.

It is obvious that my invention can be used in connection with any form of lamp mechanism, it being only necessary to obtain an up and down movement of ribbon 70.

It is obvious that a twisted cord-or small chain can be used in place of ribbon is, also that the tube 6 may be coiled into a spiral or bent into other zigzag forms than that shown. It is also obvious that the ofiice of weightl can be equally Well performed by a suitable spring. The essential principle or spirit of my invention however consists in the use of a flexible feed ribbon engaging witha retarding device on the movable carbon support, and means for varying the tension of said ribbon.

What I claimas my invention is 1. In an arc lamp, a flexible feed ribbon, engaging with a retarding device on the movable carbon support, and means for imparting an up and down movement to said ribbon, and also means for varying the tension on said ribbon, as set forth. 7 o w 2. In an arc lamp, a flexible feedribbon passing through a bent tube on the movable carbon support, and. means for imparting an 1 up and down movement tosaid ribbon, and also-means for varying the tension on said ribbon, as set forth.

3. In an arc lamp, a flexible feed ribbon passing through a tortuous passage on the movable carbon support, and means for imparting an up and down movement to said ribbon, and also means for varying the tension on said ribbon, as set forth.

4. In an arc lamp, a flexible feed ribbon engaging with a frictional retarding device on the movable carbon support, and means for imparting an up and down movement to said ribbon, and also means for varying the ten- ,sion on said ribbon as set forth.

5. In an arc lamp, a flexible feed ribbon engaging with a frictional gripping device on the movable carbon support, and means for imparting an up and down movement to said ribbon, and also means for varying the tension on said ribbon, as set forth.

6. In an arc lamp,a,flexible feed ribbon attached to, and adapted to receive movement from a core controlledby a solenoid in thelamp circuit,'-a bent tube or tortuous passage on the movable carbon support through which the feedribbon passes, and; 'a tension weight attached to the lower or free end of the feedribbon, and means for detaining said weight to cause afeed of the movable carbon, as set forth.

ALBERT W. SMITH.

Witnesses:

H. N. JENKINS, H. S. WETMORE. 

